Updated project metadata. Background: An important feature to vitamin D physiology is its gender dependence. The aim of this study was to examine whether vitamin D exerts a sexually dimorphic effect on the blood coagulation pathway among adults with overweight. Methods: This study compared the serum proteomic profiles of age and BMI-matched males (n=26) and pre-menopausal females (n=24) with overweight that attained vitamin D sufficiency after a 12-month intervention. Unprocessed serum was subjected to depletion-free, quantitative proteomic analysis using our previously published methodology. Results. A total of 1,841 proteins were profiled (p < 0.05). The analysed proteins vitamin-K dependent protein C, von Willebrand factor, fibrinogen gamma chain and multimerin-1 were ELISA validated to be differentially affected between genders by vitamin D status improvement. Conclusions: Vitamin D optimization exhibits a sexually dimorphic effect on the blood coagulation pathway among adults with overweight. This gender specific vitamin D effect should be taken into consideration in the design and interpretation of vitamin D observational and intervention studies.